The Methodist Church has now become the largest religious group in the United Kingdom to allow same-sex weddings.
On Wednesday, the Methodist Conference passed a motion to alter the definition of marriage by a vote of 254 in favor to 46 against.
Ministers who oppose the proposal will not be obliged to officiate in such marriages due to freedom of conscience laws.
In the Church of England and the Roman Catholic Church, same-sex marriage is prohibited. In the United Kingdom, however, it is accepted by the Scottish Episcopal Church, the United Reformed Church, and the Quakers.
With almost 4,000 congregations and 164,000 members, the Methodist Church is the fourth biggest Christian denomination in the United Kingdom.
The first same-sex marriages at Methodist chapels are expected to take place in the autumn, according to church authorities.
After many years of “painful conversations,” the Rev Sam McBratney, leader of the Dignity and Worth campaign group, said it was a “momentous step on the road to justice.”
“Some of us have been praying for this day for decades, and we can not believe it has finally arrived,” he added. “We are grateful to our Methodist brothers and sisters for taking the bold step of recognizing and affirming the value and worth of LGBTQ+ relationships.
“Those who oppose this move can rest assured that we will continue to work and worship with you in the Church we all love.”
Carolyn Lawrence, a former vice-president of the Methodist Conference, cautioned, however, that a “significant minority” of Methodists were “planning on leaving or resigning their membership” as a result of the decision, in an impassioned discussion.